An electroluminescence display, being a type of flat panel display, is an emissive display and has advantages of a wide viewing angle, good contrast and fast response speed. For these reasons, electroluminescence displays have attracted attention as the next generation of displays. An electroluminescence display includes a light-emitting element having an anode, a cathode, and an emission layer interposed between the anode and the cathode, and is classified as either an inorganic electroluminescence display or an organic electroluminescence display according to the type of the emission layer.
In the organic electroluminescence display, the light-emitting element is susceptible to being damaged by exterior moisture. Therefore, in order to protect the light-emitting element from exterior moisture, various techniques for encapsulating the light-emitting element using an encapsulating substrate have been developed. One of the encapsulating technologies is a method of applying a sealant on a circumference of a region in which the light-emitting element is formed, and bonding the encapsulating substrate using the sealant as a bonding medium. However, since the sealant has a defined width, it is difficult to fully prevent moisture or oxygen from the exterior environment from penetrating the sealant. In order to improve this, a technique has been developed by which sealant is applied to the entire region in which the light-emitting element is formed.
FIGS. 1a and 1b are cross-sectional views illustrating conventional methods of encapsulating an organic electroluminescence display.
Referring to FIG. 1A, a mother substrate 10 including a plurality of cell regions 10a and scribing lanes 10b defined by the cell regions 10a is provided. Each of the cell regions 10a includes a pixel region 10aa and a pad region (not shown) located in a predetermined region of the periphery of the pixel region 10aa. Then, light-emitting elements 25 are formed in the pixel regions 10aa, respectively.
Meanwhile, an encapsulating substrate 50 is provided, and a sealant 40 is applied on a predetermined region of the encapsulating substrate 50. The region where the sealant 40 is applied corresponds to the pixel region 10aa of the mother substrate 10. Then, the encapsulating substrate 50 is disposed in a way such that the surface of the encapsulating substrate 50 to which the sealant has been applied faces the mother substrate 10.
Referring to FIG. 1B, the encapsulating substrate 50 and the mother substrate 10 are bonded together by applying pressure. At this time, the sealant 40 may be squeezed out up to the circumference of the pixel region 10aa, as defined by the scribing lane 10b and the pad region by the pressure.
Subsequently, the scribing lane 10b is scribed to separate the respective cells 10a, thereby manufacturing the organic electroluminescence display. In the scribing process, the sealant 40 squeezed out to the scribing lane 10b between adjacent cells 10a may cause adjacent cells to attach to each other, thereby causing a separation defect, i.e., a scribing defect between cells 10a adjacent to each other. In addition, an additional process step is required in order to remove the sealant 40 squeezed out to the pad region, i.e., the sealant 40 incorrectly formed on the pad region.
In order to solve the problem, Korean Patent Application No. 2002-28714 discloses “Method of encapsulating OLED and OLED panel using the same.” According to the Korean Patent, the method of encapsulating OLED includes forming a partition wall by applying a first sealant to a region of an encapsulating substrate, wherein the region face a region enclosing a selected OLED of a plurality of OLEDs formed on a substrate, filling a second sealant in an opened space formed by the first sealant, bonding the encapsulating substrate and the substrate using the first and second sealants as mediums by applying pressure, and curing the first and second sealants to encapsulate the OLED. However, although the first sealant is formed of a high viscosity material, the method has a problem in that the first sealant may be squeezed out up to an outer periphery by the pressure for bonding the substrate and the encapsulating substrate. Therefore, the aforementioned problems may still occur.